Boiler for locomotive-engines



NITEI) STATES PATENT OFFICE.

ROSS IVINANS, OF BALTIMORE, MARYLAND.

BOILER FOR LOCOMOTIVE-ENGINES.

Specification of Letters Patent No. 20,116, dated April 27, 1858.

To all whom it may concern:

Be it known that I, Ross WINANs, of the city of Baltimore, in the State of Maryland, have invented a new and useful Improvement in the Construction of Locomotive-Engines for Railroads, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1, represents a side elevation of my improved locomotive; Fig. 2 a vertical longitudinal section of the fire box, and Fig. fil, a vertical transverse section of the same.

The chief object of my improvement is to adapt the locomotive to the burning of coal as a fuel, without impairing its efficiency in other respects,

It is well known that coal burns much more slowly than wood, and, in order to pro duce an equal quantity of steam in the same length of time, it is necessary to maintain a much larger quantity of coal in combustion; moreover, coal, from the smaller size of its pieces, does not permit the air to pass through a heap of it as freely as it passes through a heap of burning blocks of wood, and the combustion extends only a few inches above the grate, whatever may be the depth of coal lying thereon; hence, in order to substitute coal for wood, a much larger area of grate-surface is required and this increased grate surface necessitates the em ployment of a much larger tire-box than is necessary or desirable when wood is used as fuel. In the boilers of stationary engines and in those of vessels, where space can be easily obtained, this increase in t-he size of the fire-box can be made without diliculty and without alteration of the other parts of the mechanism; but inV locomotives, where the space is limited by a variety of circumstances and where the increase ofthe relative weight of a part of the boiler disturbs the proper distribution of weight upon the wheels, it becomes necessary, before the size of the fire-box can be increased, to modify the arrangement and construction both of it and the other parts of the locomotive, to prevent the efficiency of the engine in other respects from being impaired.

A difficulty results from increasing the size of the fire-box which arises from the manner in which it is generally constructed. The top or crown-sheet of a locomotive firebox is generally either flat or slightly curved; in either case its strength is insufficient of itself, to resist the pressure of the steam which tends to force it downward into the fire-box. In order to strengthen the crown-sheet sufficiently to enable it to sustain this pressure without yielding, it has been customary to attach it, by numerous stays, to a series of heavy beams which cross the crown sheet in the water and steam space above it and are supported at their ends, upon the vertical sides of the fire-box. If this mode of construction is pursued the number and collective weight of the beams must be increased as the hre-box is enlarged and consequently a heavy additional weight is thrown upon the hinder wheels. More over, it is customary to enlarge the shell of the boiler above the crown-sheet, to obtain a suflicient steam space and this enlargement necessarily carries with it an increase of the weight of that part of the engine.

Although the new mode of enlarging the grate described in another application for Letters Patent made simultaneously with this, obviates many of the difficulties incident to the use of an enlarged fire-box, there still remains to be overcome the disadvantage arising from the increased weight due to the increased size of the parts, which imposes an undue weight upon the hinder wheels and the object of my improvement is to obviate this disadvantage.

My invention consists of a new mode of constructing the top of the fire-box, by connecting the crown-sheet, by stays, with the outer shell of the boiler and making the space between the crown-sheet and the shell above it of sufiicient size only to permit the due circulation of water and the free escape of steam. By staying the crown-sheet directly to the exterior shell, the beams are dispensed with and the engine is relieved of their weight, while, by reducing the space between the crown-sheet and the shell, the stays are made comparatively short and light and the size and weight of the outer shell are diminished. The contraction of the space over the crown-sheet cannot however be carried beyond certain limits, for if it be made too small there will not be sufL cient room for the due circulation of the water and the free exit of steam, in which case it would become necessary to employ auxiliary water and steam spaces, the weight of which would counterbalance the advantage resulting from the contraction of the water-space and dispensing with stay-plates.

My improvement is represented in the accompanying drawings as applied to a locomotive engine having eight connected driving wheels, whose axles are all situated in front of the fire-box. The boxes of these axles are sustained by the frame, H, which terminates at the forward end of the firebox J. In this example, the hinder pair of Wheels overlaps the sides of the fire-box; consequently the width of the latter does not exceed the space between the Wheels; it is wider, however, than the space within the frame which terminates', as before-mentione'd, against its forward end. The crownsheet K, of the fire-box, is connected, by stays Z), Z2, with the exterior shell and the latter is depressed, as shown in the drawings, so that barely sufficient space is left for the free circulation of water and the escape of steam. The mode of securing the stays which I prefer is, to tap a screw-thread in the holes through which the stays are inserted and to cut a corresponding screwthread upon the stays. The latter are then screwed into the holes and they are of such length that, when in place, their ends project the usual distance beyond the faces of the plates for riveting and are riveted up. The house for the engineman (B B) is, in this instance placed upon the body of the boiler between the hinder end of the fire-box J and the smoke-box L and in rear of the smoke-pipe or chimney M and it covers the steam-dome A, at the hinder quarter of which the engineman generally stands. The floor of the engine-house is formed by two foot-boards G C, which extend from the hinder part of the fire-box to the smoke-box, and by a platform G G, which enables the engineman to pass freely from one footboard to the other, and furnishes an ample space for tools. 'Ihe throttle valve lever D, is situated at the hinder side of the steamdome in a convenient position for the engineman and the reversing lever E and the starting bars F F, for operating the valves by hand are also extended into the enginemans house.

I have represented and described my improvement as applied to a locomotive with eight drivers, but it is obvious that the number of wheels may be increased. or diminished without affecting my invention. In the example here shown the fire-box is wider than the inside of the frame, the width being limited only by the hinder pair of wheels which overlap it If however these wheels were placed a little farther forward, the width of the lire-box could be still further extended and its length correspondingly diminished.

I claim as my invention and desire to secure by Letters Patent;

The method of constructing the fire-boxes of locomotive engines, of diminished weight but of undiminished strength, by staying the crown-sheet directly to the exterior shell by means of through bolts, and contracting the space between the two. as herein described, so as to get rid of the disadvantages that would result from the excessive weight of a fire-box of the ordinary construction of sufficient capacity to burn coal as fuel, with economy.

In testimony whereof, I have hereunto subscribed my name.

Ross wINANs.

In presence of- F. F. IJAMS, P. I-I. WA'rsoN.

.Nwe-....1333 n Y 

